cleaning my chain? how often?

Purchase bicycle specific chain lube. Any brand will do. I like white lightning and rock 'n' roll. They are designed to dry and then flake off taking all the crap with it.
All you do is apply by dripping onto the chain whilst back pedalling, go make a nice cup of tea and get some bikkies to dunk in there then return to your bike and wipe the chain completely clean. Do this before and after every ride. If you ride only at the weekend, do it every weekend. On your commuter, every other day will be fine.
Be really anal about it. A $17 bottle should last a commuter about ten weeks, longer for weekend only riders. Then you'll get very long life out of your chain and in turn the rings and cassette.
Enjoy your cuppa.

I lube my chain before and after every ride this is quick and easy I use Rock n Roll blue lube wetting the chain thoroughly before wiping it clean with a rag.

Before a big race I also clean and lube my chain this is a bit more involved as I remove the chain from the bike and give it a really good clean in kerosene and get all the gunk out with a toothbrush after which I soak it in chain lube for about 10 minutes and it is better than new.

But if you are really serious about your chain here is the ultimate method. http://sheldonbrown.com/chainclean.html

The jury is out on kero. Some say yes some say no. i use a citrus based degreaser. I get it for about 3 bucks a can at supercheap auto. I clean my chain and lube after every ride. Adter every fufty kays or so i degrease the chain and cassette and clean the rest of the drive train. I then lube the cassete and chain once back on the bike. I find this method works well. Ive got about 1000 kays out of my current drivetrain with no sign of chain ware on my chain ware indicator

I have heard kero is not good but I find it seems to work the best for me.

Kero is good nothing wrong with it at all just wear gloves and do it outside where there is good ventilation.

Getting the chain off is easy enough get yourself a good quality chain breaker I would stear clear of the ones that come on a multi tool as I have only ever had problems with them.

Once the chain is off chuck it in a container of kero and scrub it with a brush of some sort an old tooth brush works fine rinse the chain in some fresh kero and leave it somwhere to dry.

Then submerge it in lube and let it soak in for 10min or so then wipe it down with a rag and put it back on the bike use an sram powerlink for this and you are done.

If you wipe down and lube your chain reguarly you shouldnt need to clean it like this very often I do mine like this maybe three or four times at the most a year usually before a big race.

Yes chain lube I use rock n roll blue its my favourite I have tried white lightning and personally thought it was crap but use what you know and like.

Well like with the chain you can give it a quick wipe and clean regularly and occasionally remove it from the wheel for a thorough clean at least take the wheel of the bike when you do clean it.

Yep I do but its only a few times a year that I do this and what doesnt go into the chain goes back in the bottle.

+1 for powerlink

Shimano and SRAM chains pins don't like chainbreakers - there's a little lip that gets broken off when you push the pin through.

Personally, I prefer Wippermann Connex links as they're easier to work with bare fingers. However you need to remember to install the link around the right way. And as I write this, I think I danged well forgot to check that when I put it back on on the weekend - the sucker was skipping in the 11T sprocket as I was racing to catch the ferry this morning. D'Oh! LOL!

Erm... aside from it's a bit lardy!